1. Field of the Invention
This invention relates to a magnetoresistive head for use with magnetic disk devices, magnetic tape devices or like magnetic devices, and more particularly to a yoke type magnetoresistive head.
2. Description of the Prior Art
A magnetoresistive head (hereinafter referred to as MR head) has a high reproducing sensitivity and a reproducing output which does not rely upon the relative speed between the magnetic recording media and the magnetic head. Therefore, the use of a magnetoresistive head is advantageous when attempting to achieve high bit density recording and miniaturization of magnetic recording devices.
Conventional MR heads are divided into two types including a type wherein a magnetoresistive element (hereinafter referred to as MR element) is disposed just above an air bearing surface and directly detects a magnetic flux generated from the magnetic recording media, and the other type wherein an MR element is disposed at a distance from an air bearing surface and detects a magnetic flux generated from the magnetic recording media by way of a magnetic yoke. While the latter type is inferior in reproducing sensitivity to the former type, it is superior in that it is high in reliability since the MR element is not exposed to the air bearing surface.
FIG. 1 is a perspective view showing an example of the general construction of a conventional MR head. The MR head is manufactured by the same process as that of a conventional thin film magnetic head and includes a pair of MR elements A 15 and B 16 magnetically coupled to upper yoke 12 and lower yoke 13, respectively. Gap 11 is defined between upper yoke 12 and lower yoke 13, and information is written onto or read out from magnetic recording media (not shown) by way of gap 11. In the MR head, back yoke 14 is coupled magnetically to MR element A 15 and MR element B 16, and terminals 17 are connected to MR element A 15 and MR element B 16 while intermediate terminal 18 is connected to an intermediate point between MR element A 15 and MR element B 16 in order to assure a high reproducing sensitivity with a differential structure.
FIG. 2 is a perspective view showing another example of a conventional MR head. The MR head includes a pair of MR elements A 25 and B 26. MR element A 25 is magnetically coupled to yoke 22 while MR element B 26 is magnetically coupled to yoke 23, and gap 21 is defined between yokes 22 and 23. In the MR head, back yoke 24 is magnetically coupled to MR element A 25 and MR element B 26, and terminals 27 are connected to MR element A 25 and MR element B 26 while intermediate terminal 28 is connected to an intermediate point between MR element A 25 and MR element B 26 with a differential structure. The track width of the MR head is defined by the thickness of yokes 22 and 23. Further, since MR element A 25 and MR element B 26 of the MR head are formed by simultaneous deposition on the same plane, a differential structure can be obtained readily.